Welcome to the New Progressive Era
Aug 04, · The geologic era in which humans have evolved and spread over the Earth is the Cenozoic Era. This time period began roughly 65 million years before the start of the 21st century. The Cenozoic Era began at the end of the Mesozoic Era when the non-avian dinosaurs and many other animals became extinct. Aug 04, · Generally, the eras used to describe the modern Earth are the Quaternary geological era and the Cenozoic evolutionary era. In the future, there may also be a historical era that the current time period, the 21st century, will belong to.
The categorization of the past into discrete, quantified named blocks of time is called periodization. Major categorization systems include cosmological time periods in the origin and mass evolution of the how to change apple id on macgeological time periods in the origin and evolution of the Earthanthropological and historical time periods in the origin and evolution of human civilization.
These can be divided broadly into prehistorical before history began to be recorded and what era are we in right now periods when written records began to be kept.
In archaeology and anthropologyprehistory is subdivided around the three-age systemthis list includes the use of the three-age system as well as a number of various designation used in reference to sub-ages within the traditional three.
The dates for each age can vary by region. On the geologic time scalethe Holocene epoch starts at the end of the last glacial period of the current ice age c.
The beginning of the Mesolithic is usually considered to correspond to the beginning of the Holocene epoch. Only for late modern contemporary history. The geologic time scale covers the extent of the existence of Earth, from about million years ago to the present day.
Geologic time units are in order of descending specificity eons, eras, periods, epochs, and ages; and the corresponding chronostratigraphic units, which measure "rock-time", are eonothems, erathems, systems, series, and stages.
The second and third timelines are each subsection of their preceding timeline as indicated by asterisks. The Cenozoic is sometimes divided into the Quaternary and Tertiary periods, although the latter is no longer used officially. From Wikipedia, the free encyclopedia. Wikipedia list article.
This article has multiple issues. Please help improve it or discuss these issues on the talk page. Learn how and when to remove these template messages. This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.
This article or section possibly contains synthesis of material which does not verifiably mention or relate to the main topic. Relevant discussion may be found on the talk page.
May Learn how and when to remove this template message. Main article: History by period. Further information: List of archaeological periods.
Further information: Universal history. Further information: History of Southeast Asia. Further information: History of the Philippines.
Further information: History of China. Further information: History of Mongolia. Further information: History of Egypt. Further information: History of Europe.
Further information: History of India. Further information: History of Japan. Main article: Timeline of the Big Bang. Study of the Ancient universe Papers, BBC News. Retrieved January 3, How to do decorative concrete floors New York Times. ISSN Retrieved July 2, Bowman, John S. Columbia Chronologies of Asian History and Culture.
ISBN Categories : History-related lists Historical timelines. Hidden how to get free message tones for iphone Articles with short description Short description is different from How to change youtube video thumbnail 2014 Articles needing additional references from December All articles needing additional references Articles that may contain original research from May Articles with multiple maintenance issues Use mdy dates from April All articles with unsourced statements Articles with unsourced statements from February Namespaces Article Talk.
Views Read Edit View history. Help Learn to edit Community portal Recent changes Upload file. Download as PDF Printable version. Very little concrete [confirmed] information is known about this epoch.
Different theories propose different views on this particular time. Grand Unification Epoch. The result of the universe expanding and cooling down during the Planck epoch. All fundamental forces except gravity are unified. The universe cools down to 10 28 kelvin. The fundamental forces are split into the strong force and the electroweak force.
The shape of the universe flattens due to cosmic inflation. Cosmic inflation has ended. Quarks are present in the universe at this point. The electroweak force is divided again into the weak force and electromagnetic force. The universe has cooled enough for quarks to form hadronsprotonsneutrons. Most hadrons and anti-hadrons annihilate each other, leaving behind leptons and anti-leptons.
Most leptons and anti-leptons annihilate each other. The universe is dominated by photons. The temperature of the universe has cooled down enough to allow atomic nuclei to form via nuclear fusion. Hydrogen and helium atoms form. The first stars and quasars form due to gravitational collapse.
Jul 19, · Geologists have systematically divided up, and named, all of Earth's roughly billion-year history. From the longest to shortest, these lengths of time are known as eons, eras, periods and. 12 rows · Sep 17, · Pre-History – Period between the appearance of Homo ("humans"; first . Jul 21, · Jul 21, We live in the Holocene Epoch, of the Quaternary Period, in the Cenozoic Era (of the Phanerozoic Eon).
Astronomers find these five chapters to be a handy way of conceiving the universe's incredibly long lifespan. Image based on logarithmic maps of the Universe put together by Princeton University researchers, and images produced by NASA based on observations made by their telescopes and roving spacecraft. If you're fortunate enough to get yourself beneath a clear sky in a dark place on a moonless night, a gorgeous space-scape of stars waits.
If you have binoculars and point them upward, you're treated to a mind-bogglingly dense backdrop of countless specks of light absolutely everywhere, stacked atop each other, burrowing outward and backward through space and time. Such is the universe of the cosmological era in which we live. It's called the Stelliferous era, and there are four others. There are many ways to consider and discuss the past, present, and future of the universe, but one in particular has caught the fancy of many astronomers.
It's worth noting that not everyone is a subscriber to the book's structure. Popular astrophysics writer Ethan C. This is where the universe begins, though what came before it and where it came from are certainly still up for discussion. It begins at the Big Bang about For the first little, and we mean very little, bit of time, spacetime and the laws of physics are thought not yet to have existed.
That weird, unknowable interval is the Planck Epoch that lasted for 10 seconds, or 10 million of a trillion of a trillion of a trillionth of a second.
Much of what we currently believe about the Planck Epoch eras is theoretical, based largely on a hybrid of general-relativity and quantum theories called quantum gravity. And it's all subject to revision. That having been said, within a second after the Big Bang finished Big Banging, inflation began, a sudden ballooning of the universe into trillion trillion times its original size. Within minutes, the plasma began cooling, and subatomic particles began to form and stick together. In the 20 minutes after the Big Bang, atoms started forming in the super-hot, fusion-fired universe.
Electrons gobbled up photons, leaving the universe opaque. About , years after the Big Bang, the universe had cooled enough that the first stable atoms capable of surviving began forming. With electrons thus occupied in atoms, photons were released as the background glow that astronomers detect today as cosmic background radiation. Inflation is believed to have happened due to the remarkable overall consistency astronomers measure in cosmic background radiation.
Astronomer Phil Plait suggests that inflation was like pulling on a bedsheet, suddenly pulling the universe's energy smooth. The smaller irregularities that survived eventually enlarged, pooling in denser areas of energy that served as seeds for star formation—their gravity pulled in dark matter and matter that eventually coalesced into the first stars.
The era we know, the age of stars, in which most matter existing in the universe takes the form of stars and galaxies during this active period. A star is formed when a gas pocket becomes denser and denser until it, and matter nearby, collapse in on itself, producing enough heat to trigger nuclear fusion in its core, the source of most of the universe's energy now.
The first stars were immense, eventually exploding as supernovas, forming many more, smaller stars. These coalesced, thanks to gravity, into galaxies. One axiom of the Stelliferous era is that the bigger the star, the more quickly it burns through its energy, and then dies, typically in just a couple of million years.
Smaller stars that consume energy more slowly stay active longer. In any event, stars — and galaxies — are coming and going all the time in this era, burning out and colliding. Scientists predict that our Milky Way galaxy, for example, will crash into and combine with the neighboring Andromeda galaxy in about 4 billion years to form a new one astronomers are calling the Milkomeda galaxy.
Our solar system may actually survive that merger, amazingly, but don't get too complacent. About a billion years later, the Sun will start running out of hydrogen and begin enlarging into its red giant phase, eventually subsuming Earth and its companions, before shrining down to a white dwarf star.
Next up is the Degenerate era, which will begin about 1 quintillion years after the Big Bang, and last until 1 duodecillion after it. This is the period during which the remains of stars we see today will dominate the universe. Were we to look up — we'll assuredly be outta here long before then — we'd see a much darker sky with just a handful of dim pinpoints of light remaining: white dwarfs , brown dwarfs , and neutron stars. These"degenerate stars" are much cooler and less light-emitting than what we see up there now.
Occasionally, star corpses will pair off into orbital death spirals that result in a brief flash of energy as they collide, and their combined mass may become low-wattage stars that will last for a little while in cosmic-timescale terms. But mostly the skies will be be bereft of light in the visible spectrum.
During this era, small brown dwarfs will wind up holding most of the available hydrogen, and black holes will grow and grow and grow, fed on stellar remains. With so little hydrogen around for the formation of new stars, the universe will grow duller and duller, colder and colder. And then the protons, having been around since the beginning of the universe will start dying off, dissolving matter, leaving behind a universe of subatomic particles, unclaimed radiation…and black holes.
For a considerable length of time, black holes will dominate the universe, pulling in what mass and energy still remain. Eventually, though, black holes evaporate, albeit super-slowly, leaking small bits of their contents as they do. Plait estimates that a small black hole 50 times the mass of the sun would take about 10 68 years to dissipate. A massive one? A 1 followed by 92 zeros. When a black hole finally drips to its last drop, a small pop of light occurs letting out some of the only remaining energy in the universe.
At that point, at 10 92 , the universe will be pretty much history, containing only low-energy, very weak subatomic particles and photons. Tonight, if it's clear, maybe you want to step outside, take a nice deep breath, and look up, grateful that we are where we are, and when we are, in spite of all the day's hardships. We've got a serious amount of temporal elbow room here, far more than we need, so not to worry, and those stars aren't going anywhere for a long, long time.
Some scientists believe the lightning-produced frequencies may be connected to our brain waves, meditation, and hypnosis. Flashes of lightning that strike around the earth about 50 times every second create low frequency electromagnetic waves that encompass the planet. These waves, dubbed Schumann Resonances, may have an affect on human behavior, think some scientists.
Kept up by the 2, or so thunderstorms that according to NASA batter our planet every moment, the Schumann Resonances can be found in the waves that go up to about 60 miles above in the lower ionosphere part of our atmosphere. They stay up there thanks to electric conductivity in the ionosphere that features charged ions, separated from neutral gas atoms in the area by solar radiation, as explains Interesting Engineering.
This allows the ionosphere to capture electromagnetic waves. The Schumann Resonances encircle the Earth, repeating the beat which has been used to study the planet's electric environment, weather, and seasons. Flowing around our planet, the waves' crests and troughs align in resonance to amplify the initial signal.
The waves were named after Winfried Otto Schumann , in honor of his seminal work on global resonances in mids. First measured in the early s, the very low-frequency waves with the base at 7. The frequency 7. The resonances fluctuate with variations in the ionosphere, with the intensity of solar radiation playing a major part. At night, for example, that part of the ionosphere becomes thinner.
The world's lighting hotspots in Asia, Africa, and South America, whose storms are seasonal and affected by whether its night or day, also influence the strength of the resonance. These waves have also been studied for their impact on humans. A study found that the frequencies may be related to different kinds of brain waves. The researchers described " real time coherence between variations in the Schumann and brain activity spectra within the 6—16 Hz band.
The Schumann Resonance of 7. Can our bodies truly be affected by electromagnetic frequencies generated by incessant lighting strikes? Certainly some of the speculation ventures into new age science. Some believe a spike in the resonance can influence people and animals, while a reversal may also be possible, where human consciousness can both be impacted by and itself impact the Schumann Resonances.
By this logic, a sudden source of global stress that produces worldwide tension would be able to change the resonances. Some have even blamed the stress caused by the Schumann Resonances that resulted from the ancient Chicxulub impact event, when a huge asteroid struck Mexico, for the demise of the dinosaurs.
While the imaginative effects of the Schumann Resonances are still up for much more scientific study, the fascination with this unique natural phenomenon continues. A study from Carnegie Mellon University tracks the travels of tarantulas since the Cretaceous period.
Whenever a movie script calls for the protagonist to be menaced by a spider, central casting typically places a call to a tarantula wrangler. Tarantulas , or theraphosids , are hairy and big — they're the largest spiders in the world — and for many people, the ultimate spider nightmare.
Reality is much tamer. Tarantulas are not actually aggressive. They're homebodies, preferring to spend their time in their burrows with their families. Females and their young hardly ever leave home, and males only go out to mate.
Stay away from them, and they'll stay away from you. This makes tarantulas' presence on six out of seven continents something of a mystery. How did such non-adventurous creatures end up in so many places? A new study published in the journal PeerJ from a team of international researchers provides the answer : They walked there as they rafted across the earth atop drifting continental masses.
Credit: Foley, et al. Together, they conducted a wide-ranging analysis of 48 spider transcriptomes , a compilation of RNA transcripts inside of cells. The researchers used the transcriptomes to construct a "family tree.
The tarantula family tree was then time-calibrated using fossil data. Tarantula fossils are rare, so the team used software to assist in the calculation using the ages of fossils from other types of spiders. Combined, the data allowed the researchers to construct a tarantula family tree dating back about million years to the Cretaceous period. Around this time, giant crocodiles were walking — yes walking on legs — in South Korea. A map of Godwana million years ago.
Tarantulas are Americans from a time when the Americas were part of the supercontinent Gondwana and still attached to Australia, Africa, Antarctica, and India. The researchers tracked tarantulas' migration atop pieces of Gondwana as the landmasses slowly assumed their current positions.
The study identifies tarantulas' ancestral ranges. Licensed under CC BY 4.